Modular rotary cutting tools, such as modular reamers, typically include two pieces, namely, a reamer portion and a shank. The reamer portion generally includes a head having a shank in the shape of a tapered cone extending therefrom. This shank is inserted into the bore of a shank member, and one or more screws are used to attach the reamer portion to the shank. The reamer head typically has outwardly projecting blade portions with cutting edges which alternate with valley portions, or, flutes.
A reamer head may be constructed of steel and may include a series of steel blade pockets positioned about the circumferential edge of the reamer head. These pockets may each include a cutting edge member seated in a pocket. Such cutting edge members may be carbide and are typically brazed to the pockets to hold them in place. A potential concern for this type of construction of a reamer head may include limitations in the ability to apply one or more coatings to the reamer head for improving the life and/or operational characteristic of the reamer head. For example, such coatings may include, without limitation, use of physical vapor deposition and/or chemical vapor deposition processes. Because of the temperatures required for such coating processes, and in order to minimize dimensional changes in the brazed construction during and/or following the coating processes, the dimensional range of the reamer head may be limited. Additionally, the selection of brazing materials may become limited to those that can withstand the temperatures of the coating process without unduly degrading in some manner. In some instances, the coating process may approach or exceed brazing temperatures, in which case such coating process may not be readily usable on a brazed reamer head due to the potentially detrimental effect of the coating process on the reamer head.
Flutes between the pocketed cutting edge members provide clearance for evacuation of chips removed from a work piece during operation of the reamer head. Generally, it is desirable to maximize the number of cutting edges and flutes about the circumferential edge of the reamer head in order to increase cutting efficiency. Accordingly, the space required for the pockets and brazing impacts the number of cutting edges and flutes which can be spaced about the finite length of the reamer head's circumferential edge.
Additionally, because of the various materials used in such a modular reamer, namely, steel, carbide, brazing material, etc., the reuse, refurbishment and/or recycling of worn reamer heads may be problematic, given the reamer's mixed material components.
In view of these considerations, significant barriers may exist in maximizing the number of cutting edges on a rotary cutting tool and/or in its reuse, refurbishment and/or recycling.